In orange: Reconstructed periods (P_m) as function of M_WD2. The top line shows M₂ = 1 M_⊙ and solar metallicity, and the bottom line shows M₂ = 2 M_⊙ and intermediate metallicity. The vertical orange bar indicates the possible values of P_m for WD0455-295.(source id 6) based on the mass of the youngest WD (M_WD2 = 0.4 M_⊙). The dashed blue line shows expected periods after stable mass transfer as function of M_WD1. The position of WD0455-295 is indicated by the vertical blue bar at the position of its mass of the first formed WD (M_WD1 = 0.44 M_⊙). The two periods are not consistent, as shown by the dotted horizontal line at P_m, stable.